:root {
  --paper: #f6f5f0;
  --band: #ecebe3;
  --panel: #ffffff;
  --ink: #16181d;
  --ink-2: #4a4d55;
  --ink-3: #63666e;
  --rule: #dcdad1;
  --rule-strong: #c4c1b5;
  --accent: #2443c4;
  --accent-ink: #ffffff;
  --accent-soft: #e6eaf9;
  --down: #b8322a;
  --down-soft: #f6e3e0;
  --foot: #15171c;
  --foot-ink: #d9d8d2;
  --foot-ink-2: #9a9a95;
  --display: "Inter Tight", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --wrap: 72rem;
  --radius: 6px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #121317;
    --band: #191b20;
    --panel: #1d1f25;
    --ink: #ecebe6;
    --ink-2: #b9b8b2;
    --ink-3: #9a9993;
    --rule: #2c2f36;
    --rule-strong: #3b3e46;
    --accent: #8ea2ff;
    --accent-ink: #0f1220;
    --accent-soft: #232a45;
    --down: #ff8a7e;
    --down-soft: #3a2220;
    --foot: #0b0c0f;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 1rem/1.6 var(--sans);
  text-rendering: optimizeLegibility;
}
a { color: var(--accent); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 2px; }
.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: clamp(1rem, 4vw, 2rem); }
.skip { position: absolute; left: -999px; top: 0; background: var(--panel); padding: 0.5rem 0.75rem; z-index: 10; }
.skip:focus { left: 1rem; top: 1rem; }

/* Header */
.site-head { border-bottom: 1px solid var(--rule); background: var(--paper); }
.site-head .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0.5rem 1.5rem; padding-block: 0.9rem; }
.mark { display: inline-flex; align-items: center; gap: 0.55rem; color: var(--ink); text-decoration: none; font: 600 1.05rem/1 var(--display); letter-spacing: -0.02em; }
.mark svg { width: 1.35rem; height: 1.35rem; }
.nav { display: flex; flex-wrap: wrap; gap: 0.25rem 1.1rem; margin: 0; padding: 0; list-style: none; font-size: 0.93rem; }
.nav a { color: var(--ink-2); text-decoration: none; padding-block: 0.25rem; }
.nav a:hover { color: var(--ink); }
.nav a[aria-current="page"] { color: var(--ink); box-shadow: inset 0 -2px 0 var(--accent); }

/* Band and headings */
.band { background: var(--band); border-bottom: 1px solid var(--rule); }
.band .wrap { padding-block: clamp(1.75rem, 5vw, 3.25rem) clamp(1.5rem, 4vw, 2.5rem); }
.crumbs { margin: 0 0 1rem; padding: 0; list-style: none; display: flex; flex-wrap: wrap; gap: 0.35rem; font-size: 0.85rem; color: var(--ink-3); }
.crumbs li + li::before { content: "/"; margin-right: 0.35rem; color: var(--rule-strong); }
.crumbs a { color: var(--ink-3); }
h1, h2, h3 { font-family: var(--display); letter-spacing: -0.025em; line-height: 1.12; margin: 0; }
h1 { font-size: clamp(2.1rem, 5.2vw, 3.6rem); font-weight: 600; letter-spacing: -0.035em; max-width: 22ch; }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.85rem); font-weight: 600; margin-top: 2.75rem; }
h3 { font-size: 1.12rem; font-weight: 600; margin-top: 1.75rem; }
.lede { margin: 1rem 0 0; font-size: 1.12rem; color: var(--ink-2); max-width: 60ch; }
.meta { margin-top: 0.9rem; font-size: 0.85rem; color: var(--ink-3); }

/* Calculator layout */
.work { padding-block: clamp(1.5rem, 4vw, 2.5rem); }
.grid { display: grid; gap: 1.5rem; }
@media (min-width: 64rem) { .grid { grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr); align-items: start; } }
.panel { background: var(--panel); border: 1px solid var(--rule); border-radius: var(--radius); padding: clamp(1rem, 3vw, 1.75rem); box-shadow: 0 1px 0 var(--rule), 0 12px 32px -24px rgba(22, 24, 29, 0.35); }
.panel h2 { margin-top: 0; font-size: 1.15rem; }
.panel-note { color: var(--ink-3); font-size: 0.88rem; margin: 0.4rem 0 0; }

.modes { display: inline-flex; border: 1px solid var(--rule-strong); border-radius: 999px; padding: 3px; margin: 0 0 1.25rem; gap: 2px; flex-wrap: wrap; }
.modes button { appearance: none; border: 0; background: transparent; color: var(--ink-2); font: 500 0.9rem/1 var(--sans); padding: 0.55rem 0.95rem; border-radius: 999px; cursor: pointer; }
.modes button[aria-selected="true"] { background: var(--ink); color: var(--paper); }

.fields { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(11rem, 1fr)); }
.field { display: grid; gap: 0.35rem; align-content: start; }
.field label, .field .label { font-size: 0.86rem; font-weight: 600; color: var(--ink-2); }
.field .hint { font-size: 0.8rem; color: var(--ink-3); }
.control { display: flex; align-items: stretch; border: 1px solid var(--rule-strong); border-radius: var(--radius); background: var(--panel); }
.control:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.control input, .control select { appearance: none; border: 0; background: transparent; color: var(--ink); font: 500 1.05rem/1.2 var(--mono); padding: 0.65rem 0.75rem; width: 100%; min-width: 0; font-variant-numeric: tabular-nums; }
.control select { font-family: var(--sans); font-size: 0.95rem; cursor: pointer; background-image: linear-gradient(45deg, transparent 50%, var(--ink-3) 50%), linear-gradient(135deg, var(--ink-3) 50%, transparent 50%); background-position: calc(100% - 16px) 55%, calc(100% - 11px) 55%; background-size: 5px 5px; background-repeat: no-repeat; padding-right: 1.9rem; }
.control input:focus, .control select:focus { outline: none; }
.control .unit { display: flex; align-items: center; padding: 0 0.75rem; color: var(--ink-3); font-size: 0.9rem; border-left: 1px solid var(--rule); }
.control.split { display: grid; grid-template-columns: minmax(0, 1fr) auto; }
.control.split select { border-left: 1px solid var(--rule); width: auto; }
.error { color: var(--down); font-size: 0.82rem; min-height: 1.1em; margin: 0; }

.chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.75rem; }
.chips button { appearance: none; border: 1px solid var(--rule-strong); background: var(--panel); color: var(--ink-2); border-radius: 999px; font: 500 0.85rem/1 var(--mono); padding: 0.45rem 0.7rem; cursor: pointer; }
.chips button:hover { border-color: var(--ink-3); color: var(--ink); }
.chips button[aria-pressed="true"] { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }

/* Readout ledger: the result table */
.ledger { width: 100%; border-collapse: collapse; margin-top: 1.5rem; font-variant-numeric: tabular-nums; }
.ledger caption { text-align: left; font-size: 0.8rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); padding-bottom: 0.5rem; }
.ledger th, .ledger td { padding: 0.7rem 0; border-top: 1px solid var(--rule); text-align: left; vertical-align: baseline; }
.ledger th { font-weight: 500; color: var(--ink-2); font-size: 0.95rem; width: 40%; }
.ledger td { font: 600 clamp(1.05rem, 2.4vw, 1.3rem)/1.2 var(--mono); text-align: right; letter-spacing: -0.01em; }
.ledger tr:last-child th, .ledger tr:last-child td { border-bottom: 1px solid var(--rule); }
.ledger td.down { color: var(--down); }
.big { margin: 1.5rem 0 0; padding: 1.1rem 1.2rem; border-radius: var(--radius); background: var(--band); border: 1px solid var(--rule); }
.big .k { display: block; font-size: 0.8rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); }
.big .v { display: block; font: 600 clamp(2rem, 6vw, 3rem)/1.1 var(--mono); letter-spacing: -0.03em; margin-top: 0.35rem; font-variant-numeric: tabular-nums; }
.big .s { display: block; color: var(--ink-2); font-size: 0.92rem; margin-top: 0.35rem; }

/* Signature: the nines ladder */
.ladder { list-style: none; margin: 0.9rem 0 0; padding: 0; }
.ladder li { display: grid; grid-template-columns: 5.2rem minmax(0, 1fr); gap: 0.25rem 0.9rem; align-items: center; padding: 0.6rem 0.5rem; border-top: 1px solid var(--rule); border-radius: 4px; }
.ladder li:last-child { border-bottom: 1px solid var(--rule); }
.ladder .pct { font: 600 1rem/1 var(--mono); font-variant-numeric: tabular-nums; }
.ladder .yr { font: 500 0.88rem/1.2 var(--mono); color: var(--ink-2); font-variant-numeric: tabular-nums; }
.ladder .bar { grid-column: 2; height: 6px; background: var(--rule); border-radius: 3px; overflow: hidden; }
.ladder .bar span { display: block; height: 100%; background: var(--down); border-radius: 3px; }
.ladder li.on { background: var(--accent-soft); border-top-color: transparent; }
.ladder li.on + li { border-top-color: transparent; }
.ladder li.on .pct { color: var(--accent); }
.ladder-foot { margin: 0.9rem 0 0; font-size: 0.9rem; color: var(--ink-2); }

/* Prose */
.prose { padding-block: 0.5rem 3rem; }
.prose .cols { display: grid; gap: 0 3rem; }
@media (min-width: 64rem) { .prose .cols { grid-template-columns: 15rem minmax(0, 1fr); } .prose .rail { position: sticky; top: 1.5rem; align-self: start; } }
.prose p, .prose li { max-width: 68ch; color: var(--ink); }
.prose p { margin: 0.9rem 0 0; }
.prose ul, .prose ol { padding-left: 1.2rem; margin: 0.9rem 0 0; }
.prose li + li { margin-top: 0.35rem; }
.prose code, .formula { font-family: var(--mono); font-size: 0.92em; background: var(--band); border: 1px solid var(--rule); border-radius: 4px; padding: 0.05rem 0.35rem; }
.formula { display: block; padding: 0.8rem 1rem; margin: 1rem 0 0; white-space: normal; overflow-wrap: anywhere; max-width: 68ch; }
.toc { font-size: 0.9rem; border-left: 2px solid var(--rule-strong); padding-left: 1rem; margin-top: 2.75rem; }
.toc p { margin: 0 0 0.5rem; font-weight: 600; color: var(--ink-3); font-size: 0.78rem; letter-spacing: 0.06em; text-transform: uppercase; }
.toc ol { list-style: none; padding: 0; margin: 0; }
.toc li { margin: 0.35rem 0 0; }
.toc a { color: var(--ink-2); text-decoration: none; }
.toc a:hover { color: var(--accent); }
.table-wrap { position: relative; overflow-x: auto; margin-top: 1rem; max-width: 100%; }
.data { border-collapse: collapse; min-width: 32rem; width: 100%; font-variant-numeric: tabular-nums; font-size: 0.95rem; }
.data th, .data td { padding: 0.55rem 0.75rem; border-bottom: 1px solid var(--rule); text-align: right; white-space: nowrap; }
.data th:first-child, .data td:first-child { text-align: left; }
.data thead th { font-size: 0.8rem; color: var(--ink-3); font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; border-bottom-color: var(--rule-strong); }
.data td { font-family: var(--mono); }
.sources { font-size: 0.9rem; color: var(--ink-2); }

/* Cards row (links to other tools and guides) */
.cards { display: grid; gap: 0; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); border-top: 1px solid var(--rule); margin-top: 1rem; }
.cards a { display: block; padding: 1.1rem 1rem 1.1rem 0; border-bottom: 1px solid var(--rule); color: var(--ink); text-decoration: none; }
.cards a strong { display: block; font: 600 1.02rem/1.3 var(--display); letter-spacing: -0.015em; }
.cards a span { display: block; font-size: 0.9rem; color: var(--ink-2); margin-top: 0.25rem; }
.cards a:hover strong { color: var(--accent); }

/* Hand-off band */
.handoff { border-top: 1px solid var(--rule); background: var(--band); }
.handoff .wrap { padding-block: 2.25rem; display: flex; flex-wrap: wrap; gap: 1rem 2rem; align-items: center; justify-content: space-between; }
.handoff p { margin: 0; max-width: 56ch; color: var(--ink-2); }
.handoff strong { display: block; color: var(--ink); font: 600 1.25rem/1.25 var(--display); letter-spacing: -0.02em; margin-bottom: 0.3rem; }
.btn { display: inline-flex; align-items: center; gap: 0.5rem; background: var(--ink); color: var(--paper); text-decoration: none; font-weight: 600; font-size: 0.95rem; padding: 0.8rem 1.15rem; border-radius: 999px; }
.btn:hover { background: var(--accent); color: var(--accent-ink); }

/* Footer */
.site-foot { background: var(--foot); color: var(--foot-ink); }
.site-foot .wrap { padding-block: 2.25rem 2.75rem; display: grid; gap: 1.5rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); font-size: 0.9rem; }
.site-foot a { color: var(--foot-ink); }
.site-foot p { margin: 0.4rem 0 0; color: var(--foot-ink-2); max-width: 46ch; }
.site-foot ul { list-style: none; margin: 0; padding: 0; }
.site-foot li + li { margin-top: 0.35rem; }
.site-foot .h { color: #fff; font-weight: 600; }

@media (prefers-reduced-motion: no-preference) {
  .ladder li, .ladder .bar span { transition: background-color 160ms ease, width 220ms ease; }
}
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.gap-top { margin-top: 0.9rem; }
.panel h2.sub { margin-top: 1.75rem; }
.prose .cols > *, .grid > * { min-width: 0; }

/* Cron generator */
.cron-grid { display: grid; gap: 1.5rem; }
.cron-grid > * { min-width: 0; }
@media (min-width: 64rem) {
  .cron-grid { grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr); grid-template-areas: "expr out" "build out" "copy out"; align-items: start; }
  .cron-expr { grid-area: expr; }
  .cron-out { grid-area: out; position: sticky; top: 1rem; }
  .cron-build { grid-area: build; }
  .cron-copy { grid-area: copy; }
}
.cron-expr .chips { margin-top: 0.5rem; }
.control input.cron-input { font-size: clamp(1.2rem, 3vw, 1.5rem); letter-spacing: 0.02em; padding-block: 0.8rem; }
.cron-fields { display: grid; gap: 1rem 0.75rem; grid-template-columns: repeat(auto-fit, minmax(8.75rem, 1fr)); margin-top: 0.9rem; }
.cron-fields .control + .control { margin-top: 0.35rem; }
.cron-fields .control select { font-size: 0.85rem; padding-block: 0.5rem; }
.big .v.text { font: 600 clamp(1.2rem, 2.6vw, 1.55rem)/1.3 var(--display); letter-spacing: -0.015em; }
.warns { list-style: none; margin: 1rem 0 0; padding: 0; }
.warns li { background: var(--down-soft); border-left: 3px solid var(--down); border-radius: 4px; padding: 0.6rem 0.8rem; font-size: 0.9rem; color: var(--ink); }
.warns li + li { margin-top: 0.5rem; }
.ledger.runs th { width: auto; font-family: var(--mono); font-size: 0.92rem; color: var(--ink); font-variant-numeric: tabular-nums; }
.ledger.runs td { font: 500 0.88rem/1.2 var(--sans); color: var(--ink-3); }
.snips { display: grid; gap: 1.1rem; margin-top: 1.1rem; }
.snips > * { min-width: 0; }
.snip-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.snip h3 { margin: 0; font-size: 0.95rem; }
.snip pre { margin: 0.45rem 0 0; padding: 0.75rem 0.9rem; background: var(--band); border: 1px solid var(--rule); border-radius: var(--radius); overflow-x: auto; font: 500 0.88rem/1.55 var(--mono); }
.snip-notes { margin: 0.4rem 0 0; padding-left: 1.1rem; font-size: 0.84rem; color: var(--ink-3); }
.snip-notes:empty { display: none; }
.copy, .try { appearance: none; border: 1px solid var(--rule-strong); background: var(--panel); color: var(--ink-2); border-radius: 999px; font: 500 0.82rem/1 var(--sans); padding: 0.45rem 0.8rem; cursor: pointer; }
.copy:hover, .try:hover { border-color: var(--accent); color: var(--accent); }
.data.text th, .data.text td { white-space: normal; text-align: left; }
.data.text td { font-family: var(--sans); }
.data.text td:first-child { white-space: nowrap; }
.data.text td.act { text-align: right; }
.data.text code { white-space: nowrap; }

/* Cron examples */
pre.code { margin: 0.9rem 0 0; padding: 0.75rem 0.9rem; max-width: 68ch; background: var(--band); border: 1px solid var(--rule); border-radius: var(--radius); white-space: pre-wrap; overflow-wrap: anywhere; font: 500 0.88rem/1.55 var(--mono); }
.data.examples th[scope="row"] { font-family: var(--sans); font-weight: 500; text-align: left; white-space: normal; color: var(--ink); }
.data.examples td.act a { white-space: nowrap; }
.prose sup { line-height: 0; }

/* Press feedback for the small buttons */
.chips button:active, .copy:active, .try:active, .modes button:active { transform: translateY(1px); }
.control select:focus-visible, .control.split input:focus-visible { outline: 2px solid var(--accent); outline-offset: -3px; border-radius: var(--radius); }
.data.fit { min-width: 0; }
.data.fit th, .data.fit td { white-space: normal; padding-inline: 0.5rem; }
.data.fit td:first-child { font-family: var(--sans); }

/* generated: nines ladder bar widths (log scale) */
.ladder li[data-nines="99"] .bar span{width:98%}
.ladder li[data-nines="99.5"] .bar span{width:89%}
.ladder li[data-nines="99.9"] .bar span{width:67%}
.ladder li[data-nines="99.95"] .bar span{width:58%}
.ladder li[data-nines="99.99"] .bar span{width:37%}
.ladder li[data-nines="99.995"] .bar span{width:27%}
.ladder li[data-nines="99.999"] .bar span{width:6%}